High Accuracy and High Sensitivity Measurements of the Electrooptic Effect in Undoped and MgO-Doped LiNbO3 Crystals

摘要

Accurate measurements of the composite electrooptic (EO) coefficients r c consisting of the EO coefficients r 13, r 33, and the piezoelectric constant d 31 in undoped and MgO-doped LiNbO3 (LN) were made by extracting the fundamental and third harmonic components from photo-detection signals of the parallel Nicol optics including the LN crystal driven by minimal sinusoidal voltage. The analysis of relationship between multiple-reflection rays in the EO crystal and the accuracy of measurement indicates that anti-reflection films must be coated on the end faces of the crystal for highly accurate measurements. Measured values of r c of undoped and MgO-doped LN crystals at a wavelength of 632.8 nm were 19.8 ± 0.1 pm/V and 19.2 ± 0.1 pm/V, respectively.